2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <linux/blkdev.h>
20 #include <linux/module.h>
21 #include <linux/buffer_head.h>
23 #include <linux/pagemap.h>
24 #include <linux/highmem.h>
25 #include <linux/time.h>
26 #include <linux/init.h>
27 #include <linux/seq_file.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mount.h>
31 #include <linux/mpage.h>
32 #include <linux/swap.h>
33 #include <linux/writeback.h>
34 #include <linux/statfs.h>
35 #include <linux/compat.h>
36 #include <linux/parser.h>
37 #include <linux/ctype.h>
38 #include <linux/namei.h>
39 #include <linux/miscdevice.h>
40 #include <linux/magic.h>
41 #include <linux/slab.h>
42 #include <linux/cleancache.h>
43 #include <linux/ratelimit.h>
44 #include <linux/btrfs.h>
46 #include "delayed-inode.h"
49 #include "transaction.h"
50 #include "btrfs_inode.h"
51 #include "print-tree.h"
56 #include "compression.h"
57 #include "rcu-string.h"
58 #include "dev-replace.h"
59 #include "free-space-cache.h"
61 #define CREATE_TRACE_POINTS
62 #include <trace/events/btrfs.h>
64 static const struct super_operations btrfs_super_ops
;
65 static struct file_system_type btrfs_fs_type
;
67 static const char *btrfs_decode_error(int errno
)
69 char *errstr
= "unknown";
73 errstr
= "IO failure";
76 errstr
= "Out of memory";
79 errstr
= "Readonly filesystem";
82 errstr
= "Object already exists";
85 errstr
= "No space left";
88 errstr
= "No such entry";
95 static void save_error_info(struct btrfs_fs_info
*fs_info
)
98 * today we only save the error info into ram. Long term we'll
99 * also send it down to the disk
101 set_bit(BTRFS_FS_STATE_ERROR
, &fs_info
->fs_state
);
104 /* btrfs handle error by forcing the filesystem readonly */
105 static void btrfs_handle_error(struct btrfs_fs_info
*fs_info
)
107 struct super_block
*sb
= fs_info
->sb
;
109 if (sb
->s_flags
& MS_RDONLY
)
112 if (test_bit(BTRFS_FS_STATE_ERROR
, &fs_info
->fs_state
)) {
113 sb
->s_flags
|= MS_RDONLY
;
114 btrfs_info(fs_info
, "forced readonly");
116 * Note that a running device replace operation is not
117 * canceled here although there is no way to update
118 * the progress. It would add the risk of a deadlock,
119 * therefore the canceling is ommited. The only penalty
120 * is that some I/O remains active until the procedure
121 * completes. The next time when the filesystem is
122 * mounted writeable again, the device replace
123 * operation continues.
130 * __btrfs_std_error decodes expected errors from the caller and
131 * invokes the approciate error response.
133 void __btrfs_std_error(struct btrfs_fs_info
*fs_info
, const char *function
,
134 unsigned int line
, int errno
, const char *fmt
, ...)
136 struct super_block
*sb
= fs_info
->sb
;
140 * Special case: if the error is EROFS, and we're already
141 * under MS_RDONLY, then it is safe here.
143 if (errno
== -EROFS
&& (sb
->s_flags
& MS_RDONLY
))
146 errstr
= btrfs_decode_error(errno
);
148 struct va_format vaf
;
155 printk(KERN_CRIT
"BTRFS error (device %s) in %s:%d: errno=%d %s (%pV)\n",
156 sb
->s_id
, function
, line
, errno
, errstr
, &vaf
);
159 printk(KERN_CRIT
"BTRFS error (device %s) in %s:%d: errno=%d %s\n",
160 sb
->s_id
, function
, line
, errno
, errstr
);
163 /* Don't go through full error handling during mount */
164 save_error_info(fs_info
);
165 if (sb
->s_flags
& MS_BORN
)
166 btrfs_handle_error(fs_info
);
169 static const char * const logtypes
[] = {
180 void btrfs_printk(const struct btrfs_fs_info
*fs_info
, const char *fmt
, ...)
182 struct super_block
*sb
= fs_info
->sb
;
184 struct va_format vaf
;
186 const char *type
= logtypes
[4];
191 kern_level
= printk_get_level(fmt
);
193 size_t size
= printk_skip_level(fmt
) - fmt
;
194 memcpy(lvl
, fmt
, size
);
197 type
= logtypes
[kern_level
- '0'];
204 printk("%sBTRFS %s (device %s): %pV\n", lvl
, type
, sb
->s_id
, &vaf
);
211 void __btrfs_std_error(struct btrfs_fs_info
*fs_info
, const char *function
,
212 unsigned int line
, int errno
, const char *fmt
, ...)
214 struct super_block
*sb
= fs_info
->sb
;
217 * Special case: if the error is EROFS, and we're already
218 * under MS_RDONLY, then it is safe here.
220 if (errno
== -EROFS
&& (sb
->s_flags
& MS_RDONLY
))
223 /* Don't go through full error handling during mount */
224 if (sb
->s_flags
& MS_BORN
) {
225 save_error_info(fs_info
);
226 btrfs_handle_error(fs_info
);
232 * We only mark the transaction aborted and then set the file system read-only.
233 * This will prevent new transactions from starting or trying to join this
236 * This means that error recovery at the call site is limited to freeing
237 * any local memory allocations and passing the error code up without
238 * further cleanup. The transaction should complete as it normally would
239 * in the call path but will return -EIO.
241 * We'll complete the cleanup in btrfs_end_transaction and
242 * btrfs_commit_transaction.
244 void __btrfs_abort_transaction(struct btrfs_trans_handle
*trans
,
245 struct btrfs_root
*root
, const char *function
,
246 unsigned int line
, int errno
)
249 * Report first abort since mount
251 if (!test_and_set_bit(BTRFS_FS_STATE_TRANS_ABORTED
,
252 &root
->fs_info
->fs_state
)) {
253 WARN(1, KERN_DEBUG
"btrfs: Transaction aborted (error %d)\n",
256 trans
->aborted
= errno
;
257 /* Nothing used. The other threads that have joined this
258 * transaction may be able to continue. */
259 if (!trans
->blocks_used
) {
262 errstr
= btrfs_decode_error(errno
);
263 btrfs_warn(root
->fs_info
,
264 "%s:%d: Aborting unused transaction(%s).",
265 function
, line
, errstr
);
268 ACCESS_ONCE(trans
->transaction
->aborted
) = errno
;
269 __btrfs_std_error(root
->fs_info
, function
, line
, errno
, NULL
);
272 * __btrfs_panic decodes unexpected, fatal errors from the caller,
273 * issues an alert, and either panics or BUGs, depending on mount options.
275 void __btrfs_panic(struct btrfs_fs_info
*fs_info
, const char *function
,
276 unsigned int line
, int errno
, const char *fmt
, ...)
278 char *s_id
= "<unknown>";
280 struct va_format vaf
= { .fmt
= fmt
};
284 s_id
= fs_info
->sb
->s_id
;
289 errstr
= btrfs_decode_error(errno
);
290 if (fs_info
&& (fs_info
->mount_opt
& BTRFS_MOUNT_PANIC_ON_FATAL_ERROR
))
291 panic(KERN_CRIT
"BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
292 s_id
, function
, line
, &vaf
, errno
, errstr
);
294 printk(KERN_CRIT
"BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
295 s_id
, function
, line
, &vaf
, errno
, errstr
);
297 /* Caller calls BUG() */
300 static void btrfs_put_super(struct super_block
*sb
)
302 (void)close_ctree(btrfs_sb(sb
)->tree_root
);
303 /* FIXME: need to fix VFS to return error? */
304 /* AV: return it _where_? ->put_super() can be triggered by any number
305 * of async events, up to and including delivery of SIGKILL to the
306 * last process that kept it busy. Or segfault in the aforementioned
307 * process... Whom would you report that to?
312 Opt_degraded
, Opt_subvol
, Opt_subvolid
, Opt_device
, Opt_nodatasum
,
313 Opt_nodatacow
, Opt_max_inline
, Opt_alloc_start
, Opt_nobarrier
, Opt_ssd
,
314 Opt_nossd
, Opt_ssd_spread
, Opt_thread_pool
, Opt_noacl
, Opt_compress
,
315 Opt_compress_type
, Opt_compress_force
, Opt_compress_force_type
,
316 Opt_notreelog
, Opt_ratio
, Opt_flushoncommit
, Opt_discard
,
317 Opt_space_cache
, Opt_clear_cache
, Opt_user_subvol_rm_allowed
,
318 Opt_enospc_debug
, Opt_subvolrootid
, Opt_defrag
, Opt_inode_cache
,
319 Opt_no_space_cache
, Opt_recovery
, Opt_skip_balance
,
320 Opt_check_integrity
, Opt_check_integrity_including_extent_data
,
321 Opt_check_integrity_print_mask
, Opt_fatal_errors
,
325 static match_table_t tokens
= {
326 {Opt_degraded
, "degraded"},
327 {Opt_subvol
, "subvol=%s"},
328 {Opt_subvolid
, "subvolid=%d"},
329 {Opt_device
, "device=%s"},
330 {Opt_nodatasum
, "nodatasum"},
331 {Opt_nodatacow
, "nodatacow"},
332 {Opt_nobarrier
, "nobarrier"},
333 {Opt_max_inline
, "max_inline=%s"},
334 {Opt_alloc_start
, "alloc_start=%s"},
335 {Opt_thread_pool
, "thread_pool=%d"},
336 {Opt_compress
, "compress"},
337 {Opt_compress_type
, "compress=%s"},
338 {Opt_compress_force
, "compress-force"},
339 {Opt_compress_force_type
, "compress-force=%s"},
341 {Opt_ssd_spread
, "ssd_spread"},
342 {Opt_nossd
, "nossd"},
343 {Opt_noacl
, "noacl"},
344 {Opt_notreelog
, "notreelog"},
345 {Opt_flushoncommit
, "flushoncommit"},
346 {Opt_ratio
, "metadata_ratio=%d"},
347 {Opt_discard
, "discard"},
348 {Opt_space_cache
, "space_cache"},
349 {Opt_clear_cache
, "clear_cache"},
350 {Opt_user_subvol_rm_allowed
, "user_subvol_rm_allowed"},
351 {Opt_enospc_debug
, "enospc_debug"},
352 {Opt_subvolrootid
, "subvolrootid=%d"},
353 {Opt_defrag
, "autodefrag"},
354 {Opt_inode_cache
, "inode_cache"},
355 {Opt_no_space_cache
, "nospace_cache"},
356 {Opt_recovery
, "recovery"},
357 {Opt_skip_balance
, "skip_balance"},
358 {Opt_check_integrity
, "check_int"},
359 {Opt_check_integrity_including_extent_data
, "check_int_data"},
360 {Opt_check_integrity_print_mask
, "check_int_print_mask=%d"},
361 {Opt_fatal_errors
, "fatal_errors=%s"},
366 * Regular mount options parser. Everything that is needed only when
367 * reading in a new superblock is parsed here.
368 * XXX JDM: This needs to be cleaned up for remount.
370 int btrfs_parse_options(struct btrfs_root
*root
, char *options
)
372 struct btrfs_fs_info
*info
= root
->fs_info
;
373 substring_t args
[MAX_OPT_ARGS
];
374 char *p
, *num
, *orig
= NULL
;
379 bool compress_force
= false;
381 cache_gen
= btrfs_super_cache_generation(root
->fs_info
->super_copy
);
383 btrfs_set_opt(info
->mount_opt
, SPACE_CACHE
);
389 * strsep changes the string, duplicate it because parse_options
392 options
= kstrdup(options
, GFP_NOFS
);
398 while ((p
= strsep(&options
, ",")) != NULL
) {
403 token
= match_token(p
, tokens
, args
);
406 printk(KERN_INFO
"btrfs: allowing degraded mounts\n");
407 btrfs_set_opt(info
->mount_opt
, DEGRADED
);
411 case Opt_subvolrootid
:
414 * These are parsed by btrfs_parse_early_options
415 * and can be happily ignored here.
419 printk(KERN_INFO
"btrfs: setting nodatasum\n");
420 btrfs_set_opt(info
->mount_opt
, NODATASUM
);
423 if (!btrfs_test_opt(root
, COMPRESS
) ||
424 !btrfs_test_opt(root
, FORCE_COMPRESS
)) {
425 printk(KERN_INFO
"btrfs: setting nodatacow, compression disabled\n");
427 printk(KERN_INFO
"btrfs: setting nodatacow\n");
429 info
->compress_type
= BTRFS_COMPRESS_NONE
;
430 btrfs_clear_opt(info
->mount_opt
, COMPRESS
);
431 btrfs_clear_opt(info
->mount_opt
, FORCE_COMPRESS
);
432 btrfs_set_opt(info
->mount_opt
, NODATACOW
);
433 btrfs_set_opt(info
->mount_opt
, NODATASUM
);
435 case Opt_compress_force
:
436 case Opt_compress_force_type
:
437 compress_force
= true;
440 case Opt_compress_type
:
441 if (token
== Opt_compress
||
442 token
== Opt_compress_force
||
443 strcmp(args
[0].from
, "zlib") == 0) {
444 compress_type
= "zlib";
445 info
->compress_type
= BTRFS_COMPRESS_ZLIB
;
446 btrfs_set_opt(info
->mount_opt
, COMPRESS
);
447 btrfs_clear_opt(info
->mount_opt
, NODATACOW
);
448 btrfs_clear_opt(info
->mount_opt
, NODATASUM
);
449 } else if (strcmp(args
[0].from
, "lzo") == 0) {
450 compress_type
= "lzo";
451 info
->compress_type
= BTRFS_COMPRESS_LZO
;
452 btrfs_set_opt(info
->mount_opt
, COMPRESS
);
453 btrfs_clear_opt(info
->mount_opt
, NODATACOW
);
454 btrfs_clear_opt(info
->mount_opt
, NODATASUM
);
455 btrfs_set_fs_incompat(info
, COMPRESS_LZO
);
456 } else if (strncmp(args
[0].from
, "no", 2) == 0) {
457 compress_type
= "no";
458 info
->compress_type
= BTRFS_COMPRESS_NONE
;
459 btrfs_clear_opt(info
->mount_opt
, COMPRESS
);
460 btrfs_clear_opt(info
->mount_opt
, FORCE_COMPRESS
);
461 compress_force
= false;
467 if (compress_force
) {
468 btrfs_set_opt(info
->mount_opt
, FORCE_COMPRESS
);
469 pr_info("btrfs: force %s compression\n",
472 pr_info("btrfs: use %s compression\n",
476 printk(KERN_INFO
"btrfs: use ssd allocation scheme\n");
477 btrfs_set_opt(info
->mount_opt
, SSD
);
480 printk(KERN_INFO
"btrfs: use spread ssd "
481 "allocation scheme\n");
482 btrfs_set_opt(info
->mount_opt
, SSD
);
483 btrfs_set_opt(info
->mount_opt
, SSD_SPREAD
);
486 printk(KERN_INFO
"btrfs: not using ssd allocation "
488 btrfs_set_opt(info
->mount_opt
, NOSSD
);
489 btrfs_clear_opt(info
->mount_opt
, SSD
);
490 btrfs_clear_opt(info
->mount_opt
, SSD_SPREAD
);
493 printk(KERN_INFO
"btrfs: turning off barriers\n");
494 btrfs_set_opt(info
->mount_opt
, NOBARRIER
);
496 case Opt_thread_pool
:
498 match_int(&args
[0], &intarg
);
500 info
->thread_pool_size
= intarg
;
503 num
= match_strdup(&args
[0]);
505 info
->max_inline
= memparse(num
, NULL
);
508 if (info
->max_inline
) {
509 info
->max_inline
= max_t(u64
,
513 printk(KERN_INFO
"btrfs: max_inline at %llu\n",
514 (unsigned long long)info
->max_inline
);
517 case Opt_alloc_start
:
518 num
= match_strdup(&args
[0]);
520 mutex_lock(&info
->chunk_mutex
);
521 info
->alloc_start
= memparse(num
, NULL
);
522 mutex_unlock(&info
->chunk_mutex
);
525 "btrfs: allocations start at %llu\n",
526 (unsigned long long)info
->alloc_start
);
530 root
->fs_info
->sb
->s_flags
&= ~MS_POSIXACL
;
533 printk(KERN_INFO
"btrfs: disabling tree log\n");
534 btrfs_set_opt(info
->mount_opt
, NOTREELOG
);
536 case Opt_flushoncommit
:
537 printk(KERN_INFO
"btrfs: turning on flush-on-commit\n");
538 btrfs_set_opt(info
->mount_opt
, FLUSHONCOMMIT
);
542 match_int(&args
[0], &intarg
);
544 info
->metadata_ratio
= intarg
;
545 printk(KERN_INFO
"btrfs: metadata ratio %d\n",
546 info
->metadata_ratio
);
550 btrfs_set_opt(info
->mount_opt
, DISCARD
);
552 case Opt_space_cache
:
553 btrfs_set_opt(info
->mount_opt
, SPACE_CACHE
);
555 case Opt_no_space_cache
:
556 printk(KERN_INFO
"btrfs: disabling disk space caching\n");
557 btrfs_clear_opt(info
->mount_opt
, SPACE_CACHE
);
559 case Opt_inode_cache
:
560 printk(KERN_INFO
"btrfs: enabling inode map caching\n");
561 btrfs_set_opt(info
->mount_opt
, INODE_MAP_CACHE
);
563 case Opt_clear_cache
:
564 printk(KERN_INFO
"btrfs: force clearing of disk cache\n");
565 btrfs_set_opt(info
->mount_opt
, CLEAR_CACHE
);
567 case Opt_user_subvol_rm_allowed
:
568 btrfs_set_opt(info
->mount_opt
, USER_SUBVOL_RM_ALLOWED
);
570 case Opt_enospc_debug
:
571 btrfs_set_opt(info
->mount_opt
, ENOSPC_DEBUG
);
574 printk(KERN_INFO
"btrfs: enabling auto defrag\n");
575 btrfs_set_opt(info
->mount_opt
, AUTO_DEFRAG
);
578 printk(KERN_INFO
"btrfs: enabling auto recovery\n");
579 btrfs_set_opt(info
->mount_opt
, RECOVERY
);
581 case Opt_skip_balance
:
582 btrfs_set_opt(info
->mount_opt
, SKIP_BALANCE
);
584 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
585 case Opt_check_integrity_including_extent_data
:
586 printk(KERN_INFO
"btrfs: enabling check integrity"
587 " including extent data\n");
588 btrfs_set_opt(info
->mount_opt
,
589 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA
);
590 btrfs_set_opt(info
->mount_opt
, CHECK_INTEGRITY
);
592 case Opt_check_integrity
:
593 printk(KERN_INFO
"btrfs: enabling check integrity\n");
594 btrfs_set_opt(info
->mount_opt
, CHECK_INTEGRITY
);
596 case Opt_check_integrity_print_mask
:
598 match_int(&args
[0], &intarg
);
600 info
->check_integrity_print_mask
= intarg
;
601 printk(KERN_INFO
"btrfs:"
602 " check_integrity_print_mask 0x%x\n",
603 info
->check_integrity_print_mask
);
607 case Opt_check_integrity_including_extent_data
:
608 case Opt_check_integrity
:
609 case Opt_check_integrity_print_mask
:
610 printk(KERN_ERR
"btrfs: support for check_integrity*"
611 " not compiled in!\n");
615 case Opt_fatal_errors
:
616 if (strcmp(args
[0].from
, "panic") == 0)
617 btrfs_set_opt(info
->mount_opt
,
618 PANIC_ON_FATAL_ERROR
);
619 else if (strcmp(args
[0].from
, "bug") == 0)
620 btrfs_clear_opt(info
->mount_opt
,
621 PANIC_ON_FATAL_ERROR
);
628 printk(KERN_INFO
"btrfs: unrecognized mount option "
637 if (!ret
&& btrfs_test_opt(root
, SPACE_CACHE
))
638 printk(KERN_INFO
"btrfs: disk space caching is enabled\n");
644 * Parse mount options that are required early in the mount process.
646 * All other options will be parsed on much later in the mount process and
647 * only when we need to allocate a new super block.
649 static int btrfs_parse_early_options(const char *options
, fmode_t flags
,
650 void *holder
, char **subvol_name
, u64
*subvol_objectid
,
651 struct btrfs_fs_devices
**fs_devices
)
653 substring_t args
[MAX_OPT_ARGS
];
654 char *device_name
, *opts
, *orig
, *p
;
662 * strsep changes the string, duplicate it because parse_options
665 opts
= kstrdup(options
, GFP_KERNEL
);
670 while ((p
= strsep(&opts
, ",")) != NULL
) {
675 token
= match_token(p
, tokens
, args
);
679 *subvol_name
= match_strdup(&args
[0]);
683 error
= match_int(&args
[0], &intarg
);
685 /* we want the original fs_tree */
688 BTRFS_FS_TREE_OBJECTID
;
690 *subvol_objectid
= intarg
;
693 case Opt_subvolrootid
:
695 "btrfs: 'subvolrootid' mount option is deprecated and has no effect\n");
698 device_name
= match_strdup(&args
[0]);
703 error
= btrfs_scan_one_device(device_name
,
704 flags
, holder
, fs_devices
);
719 static struct dentry
*get_default_root(struct super_block
*sb
,
722 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
723 struct btrfs_root
*root
= fs_info
->tree_root
;
724 struct btrfs_root
*new_root
;
725 struct btrfs_dir_item
*di
;
726 struct btrfs_path
*path
;
727 struct btrfs_key location
;
733 * We have a specific subvol we want to mount, just setup location and
734 * go look up the root.
736 if (subvol_objectid
) {
737 location
.objectid
= subvol_objectid
;
738 location
.type
= BTRFS_ROOT_ITEM_KEY
;
739 location
.offset
= (u64
)-1;
743 path
= btrfs_alloc_path();
745 return ERR_PTR(-ENOMEM
);
746 path
->leave_spinning
= 1;
749 * Find the "default" dir item which points to the root item that we
750 * will mount by default if we haven't been given a specific subvolume
753 dir_id
= btrfs_super_root_dir(fs_info
->super_copy
);
754 di
= btrfs_lookup_dir_item(NULL
, root
, path
, dir_id
, "default", 7, 0);
756 btrfs_free_path(path
);
761 * Ok the default dir item isn't there. This is weird since
762 * it's always been there, but don't freak out, just try and
763 * mount to root most subvolume.
765 btrfs_free_path(path
);
766 dir_id
= BTRFS_FIRST_FREE_OBJECTID
;
767 new_root
= fs_info
->fs_root
;
771 btrfs_dir_item_key_to_cpu(path
->nodes
[0], di
, &location
);
772 btrfs_free_path(path
);
775 new_root
= btrfs_read_fs_root_no_name(fs_info
, &location
);
776 if (IS_ERR(new_root
))
777 return ERR_CAST(new_root
);
779 if (btrfs_root_refs(&new_root
->root_item
) == 0)
780 return ERR_PTR(-ENOENT
);
782 dir_id
= btrfs_root_dirid(&new_root
->root_item
);
784 location
.objectid
= dir_id
;
785 location
.type
= BTRFS_INODE_ITEM_KEY
;
788 inode
= btrfs_iget(sb
, &location
, new_root
, &new);
790 return ERR_CAST(inode
);
793 * If we're just mounting the root most subvol put the inode and return
794 * a reference to the dentry. We will have already gotten a reference
795 * to the inode in btrfs_fill_super so we're good to go.
797 if (!new && sb
->s_root
->d_inode
== inode
) {
799 return dget(sb
->s_root
);
802 return d_obtain_alias(inode
);
805 static int btrfs_fill_super(struct super_block
*sb
,
806 struct btrfs_fs_devices
*fs_devices
,
807 void *data
, int silent
)
810 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
811 struct btrfs_key key
;
814 sb
->s_maxbytes
= MAX_LFS_FILESIZE
;
815 sb
->s_magic
= BTRFS_SUPER_MAGIC
;
816 sb
->s_op
= &btrfs_super_ops
;
817 sb
->s_d_op
= &btrfs_dentry_operations
;
818 sb
->s_export_op
= &btrfs_export_ops
;
819 sb
->s_xattr
= btrfs_xattr_handlers
;
821 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
822 sb
->s_flags
|= MS_POSIXACL
;
824 sb
->s_flags
|= MS_I_VERSION
;
825 err
= open_ctree(sb
, fs_devices
, (char *)data
);
827 printk("btrfs: open_ctree failed\n");
831 key
.objectid
= BTRFS_FIRST_FREE_OBJECTID
;
832 key
.type
= BTRFS_INODE_ITEM_KEY
;
834 inode
= btrfs_iget(sb
, &key
, fs_info
->fs_root
, NULL
);
836 err
= PTR_ERR(inode
);
840 sb
->s_root
= d_make_root(inode
);
846 save_mount_options(sb
, data
);
847 cleancache_init_fs(sb
);
848 sb
->s_flags
|= MS_ACTIVE
;
852 close_ctree(fs_info
->tree_root
);
856 int btrfs_sync_fs(struct super_block
*sb
, int wait
)
858 struct btrfs_trans_handle
*trans
;
859 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
860 struct btrfs_root
*root
= fs_info
->tree_root
;
862 trace_btrfs_sync_fs(wait
);
865 filemap_flush(fs_info
->btree_inode
->i_mapping
);
869 btrfs_wait_ordered_extents(root
, 1);
871 trans
= btrfs_attach_transaction_barrier(root
);
873 /* no transaction, don't bother */
874 if (PTR_ERR(trans
) == -ENOENT
)
876 return PTR_ERR(trans
);
878 return btrfs_commit_transaction(trans
, root
);
881 static int btrfs_show_options(struct seq_file
*seq
, struct dentry
*dentry
)
883 struct btrfs_fs_info
*info
= btrfs_sb(dentry
->d_sb
);
884 struct btrfs_root
*root
= info
->tree_root
;
887 if (btrfs_test_opt(root
, DEGRADED
))
888 seq_puts(seq
, ",degraded");
889 if (btrfs_test_opt(root
, NODATASUM
))
890 seq_puts(seq
, ",nodatasum");
891 if (btrfs_test_opt(root
, NODATACOW
))
892 seq_puts(seq
, ",nodatacow");
893 if (btrfs_test_opt(root
, NOBARRIER
))
894 seq_puts(seq
, ",nobarrier");
895 if (info
->max_inline
!= 8192 * 1024)
896 seq_printf(seq
, ",max_inline=%llu",
897 (unsigned long long)info
->max_inline
);
898 if (info
->alloc_start
!= 0)
899 seq_printf(seq
, ",alloc_start=%llu",
900 (unsigned long long)info
->alloc_start
);
901 if (info
->thread_pool_size
!= min_t(unsigned long,
902 num_online_cpus() + 2, 8))
903 seq_printf(seq
, ",thread_pool=%d", info
->thread_pool_size
);
904 if (btrfs_test_opt(root
, COMPRESS
)) {
905 if (info
->compress_type
== BTRFS_COMPRESS_ZLIB
)
906 compress_type
= "zlib";
908 compress_type
= "lzo";
909 if (btrfs_test_opt(root
, FORCE_COMPRESS
))
910 seq_printf(seq
, ",compress-force=%s", compress_type
);
912 seq_printf(seq
, ",compress=%s", compress_type
);
914 if (btrfs_test_opt(root
, NOSSD
))
915 seq_puts(seq
, ",nossd");
916 if (btrfs_test_opt(root
, SSD_SPREAD
))
917 seq_puts(seq
, ",ssd_spread");
918 else if (btrfs_test_opt(root
, SSD
))
919 seq_puts(seq
, ",ssd");
920 if (btrfs_test_opt(root
, NOTREELOG
))
921 seq_puts(seq
, ",notreelog");
922 if (btrfs_test_opt(root
, FLUSHONCOMMIT
))
923 seq_puts(seq
, ",flushoncommit");
924 if (btrfs_test_opt(root
, DISCARD
))
925 seq_puts(seq
, ",discard");
926 if (!(root
->fs_info
->sb
->s_flags
& MS_POSIXACL
))
927 seq_puts(seq
, ",noacl");
928 if (btrfs_test_opt(root
, SPACE_CACHE
))
929 seq_puts(seq
, ",space_cache");
931 seq_puts(seq
, ",nospace_cache");
932 if (btrfs_test_opt(root
, CLEAR_CACHE
))
933 seq_puts(seq
, ",clear_cache");
934 if (btrfs_test_opt(root
, USER_SUBVOL_RM_ALLOWED
))
935 seq_puts(seq
, ",user_subvol_rm_allowed");
936 if (btrfs_test_opt(root
, ENOSPC_DEBUG
))
937 seq_puts(seq
, ",enospc_debug");
938 if (btrfs_test_opt(root
, AUTO_DEFRAG
))
939 seq_puts(seq
, ",autodefrag");
940 if (btrfs_test_opt(root
, INODE_MAP_CACHE
))
941 seq_puts(seq
, ",inode_cache");
942 if (btrfs_test_opt(root
, SKIP_BALANCE
))
943 seq_puts(seq
, ",skip_balance");
944 if (btrfs_test_opt(root
, PANIC_ON_FATAL_ERROR
))
945 seq_puts(seq
, ",fatal_errors=panic");
949 static int btrfs_test_super(struct super_block
*s
, void *data
)
951 struct btrfs_fs_info
*p
= data
;
952 struct btrfs_fs_info
*fs_info
= btrfs_sb(s
);
954 return fs_info
->fs_devices
== p
->fs_devices
;
957 static int btrfs_set_super(struct super_block
*s
, void *data
)
959 int err
= set_anon_super(s
, data
);
966 * subvolumes are identified by ino 256
968 static inline int is_subvolume_inode(struct inode
*inode
)
970 if (inode
&& inode
->i_ino
== BTRFS_FIRST_FREE_OBJECTID
)
976 * This will strip out the subvol=%s argument for an argument string and add
977 * subvolid=0 to make sure we get the actual tree root for path walking to the
980 static char *setup_root_args(char *args
)
982 unsigned len
= strlen(args
) + 2 + 1;
983 char *src
, *dst
, *buf
;
986 * We need the same args as before, but with this substitution:
987 * s!subvol=[^,]+!subvolid=0!
989 * Since the replacement string is up to 2 bytes longer than the
990 * original, allocate strlen(args) + 2 + 1 bytes.
993 src
= strstr(args
, "subvol=");
994 /* This shouldn't happen, but just in case.. */
998 buf
= dst
= kmalloc(len
, GFP_NOFS
);
1003 * If the subvol= arg is not at the start of the string,
1004 * copy whatever precedes it into buf.
1009 dst
+= strlen(args
);
1012 strcpy(dst
, "subvolid=0");
1013 dst
+= strlen("subvolid=0");
1016 * If there is a "," after the original subvol=... string,
1017 * copy that suffix into our buffer. Otherwise, we're done.
1019 src
= strchr(src
, ',');
1026 static struct dentry
*mount_subvol(const char *subvol_name
, int flags
,
1027 const char *device_name
, char *data
)
1029 struct dentry
*root
;
1030 struct vfsmount
*mnt
;
1033 newargs
= setup_root_args(data
);
1035 return ERR_PTR(-ENOMEM
);
1036 mnt
= vfs_kern_mount(&btrfs_fs_type
, flags
, device_name
,
1040 return ERR_CAST(mnt
);
1042 root
= mount_subtree(mnt
, subvol_name
);
1044 if (!IS_ERR(root
) && !is_subvolume_inode(root
->d_inode
)) {
1045 struct super_block
*s
= root
->d_sb
;
1047 root
= ERR_PTR(-EINVAL
);
1048 deactivate_locked_super(s
);
1049 printk(KERN_ERR
"btrfs: '%s' is not a valid subvolume\n",
1057 * Find a superblock for the given device / mount point.
1059 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
1060 * for multiple device setup. Make sure to keep it in sync.
1062 static struct dentry
*btrfs_mount(struct file_system_type
*fs_type
, int flags
,
1063 const char *device_name
, void *data
)
1065 struct block_device
*bdev
= NULL
;
1066 struct super_block
*s
;
1067 struct dentry
*root
;
1068 struct btrfs_fs_devices
*fs_devices
= NULL
;
1069 struct btrfs_fs_info
*fs_info
= NULL
;
1070 fmode_t mode
= FMODE_READ
;
1071 char *subvol_name
= NULL
;
1072 u64 subvol_objectid
= 0;
1075 if (!(flags
& MS_RDONLY
))
1076 mode
|= FMODE_WRITE
;
1078 error
= btrfs_parse_early_options(data
, mode
, fs_type
,
1079 &subvol_name
, &subvol_objectid
,
1083 return ERR_PTR(error
);
1087 root
= mount_subvol(subvol_name
, flags
, device_name
, data
);
1092 error
= btrfs_scan_one_device(device_name
, mode
, fs_type
, &fs_devices
);
1094 return ERR_PTR(error
);
1097 * Setup a dummy root and fs_info for test/set super. This is because
1098 * we don't actually fill this stuff out until open_ctree, but we need
1099 * it for searching for existing supers, so this lets us do that and
1100 * then open_ctree will properly initialize everything later.
1102 fs_info
= kzalloc(sizeof(struct btrfs_fs_info
), GFP_NOFS
);
1104 return ERR_PTR(-ENOMEM
);
1106 fs_info
->fs_devices
= fs_devices
;
1108 fs_info
->super_copy
= kzalloc(BTRFS_SUPER_INFO_SIZE
, GFP_NOFS
);
1109 fs_info
->super_for_commit
= kzalloc(BTRFS_SUPER_INFO_SIZE
, GFP_NOFS
);
1110 if (!fs_info
->super_copy
|| !fs_info
->super_for_commit
) {
1115 error
= btrfs_open_devices(fs_devices
, mode
, fs_type
);
1119 if (!(flags
& MS_RDONLY
) && fs_devices
->rw_devices
== 0) {
1121 goto error_close_devices
;
1124 bdev
= fs_devices
->latest_bdev
;
1125 s
= sget(fs_type
, btrfs_test_super
, btrfs_set_super
, flags
| MS_NOSEC
,
1129 goto error_close_devices
;
1133 btrfs_close_devices(fs_devices
);
1134 free_fs_info(fs_info
);
1135 if ((flags
^ s
->s_flags
) & MS_RDONLY
)
1138 char b
[BDEVNAME_SIZE
];
1140 strlcpy(s
->s_id
, bdevname(bdev
, b
), sizeof(s
->s_id
));
1141 btrfs_sb(s
)->bdev_holder
= fs_type
;
1142 error
= btrfs_fill_super(s
, fs_devices
, data
,
1143 flags
& MS_SILENT
? 1 : 0);
1146 root
= !error
? get_default_root(s
, subvol_objectid
) : ERR_PTR(error
);
1148 deactivate_locked_super(s
);
1152 error_close_devices
:
1153 btrfs_close_devices(fs_devices
);
1155 free_fs_info(fs_info
);
1156 return ERR_PTR(error
);
1159 static void btrfs_set_max_workers(struct btrfs_workers
*workers
, int new_limit
)
1161 spin_lock_irq(&workers
->lock
);
1162 workers
->max_workers
= new_limit
;
1163 spin_unlock_irq(&workers
->lock
);
1166 static void btrfs_resize_thread_pool(struct btrfs_fs_info
*fs_info
,
1167 int new_pool_size
, int old_pool_size
)
1169 if (new_pool_size
== old_pool_size
)
1172 fs_info
->thread_pool_size
= new_pool_size
;
1174 printk(KERN_INFO
"btrfs: resize thread pool %d -> %d\n",
1175 old_pool_size
, new_pool_size
);
1177 btrfs_set_max_workers(&fs_info
->generic_worker
, new_pool_size
);
1178 btrfs_set_max_workers(&fs_info
->workers
, new_pool_size
);
1179 btrfs_set_max_workers(&fs_info
->delalloc_workers
, new_pool_size
);
1180 btrfs_set_max_workers(&fs_info
->submit_workers
, new_pool_size
);
1181 btrfs_set_max_workers(&fs_info
->caching_workers
, new_pool_size
);
1182 btrfs_set_max_workers(&fs_info
->fixup_workers
, new_pool_size
);
1183 btrfs_set_max_workers(&fs_info
->endio_workers
, new_pool_size
);
1184 btrfs_set_max_workers(&fs_info
->endio_meta_workers
, new_pool_size
);
1185 btrfs_set_max_workers(&fs_info
->endio_meta_write_workers
, new_pool_size
);
1186 btrfs_set_max_workers(&fs_info
->endio_write_workers
, new_pool_size
);
1187 btrfs_set_max_workers(&fs_info
->endio_freespace_worker
, new_pool_size
);
1188 btrfs_set_max_workers(&fs_info
->delayed_workers
, new_pool_size
);
1189 btrfs_set_max_workers(&fs_info
->readahead_workers
, new_pool_size
);
1190 btrfs_set_max_workers(&fs_info
->scrub_wr_completion_workers
,
1194 static inline void btrfs_remount_prepare(struct btrfs_fs_info
*fs_info
)
1196 set_bit(BTRFS_FS_STATE_REMOUNTING
, &fs_info
->fs_state
);
1199 static inline void btrfs_remount_begin(struct btrfs_fs_info
*fs_info
,
1200 unsigned long old_opts
, int flags
)
1202 if (btrfs_raw_test_opt(old_opts
, AUTO_DEFRAG
) &&
1203 (!btrfs_raw_test_opt(fs_info
->mount_opt
, AUTO_DEFRAG
) ||
1204 (flags
& MS_RDONLY
))) {
1205 /* wait for any defraggers to finish */
1206 wait_event(fs_info
->transaction_wait
,
1207 (atomic_read(&fs_info
->defrag_running
) == 0));
1208 if (flags
& MS_RDONLY
)
1209 sync_filesystem(fs_info
->sb
);
1213 static inline void btrfs_remount_cleanup(struct btrfs_fs_info
*fs_info
,
1214 unsigned long old_opts
)
1217 * We need cleanup all defragable inodes if the autodefragment is
1218 * close or the fs is R/O.
1220 if (btrfs_raw_test_opt(old_opts
, AUTO_DEFRAG
) &&
1221 (!btrfs_raw_test_opt(fs_info
->mount_opt
, AUTO_DEFRAG
) ||
1222 (fs_info
->sb
->s_flags
& MS_RDONLY
))) {
1223 btrfs_cleanup_defrag_inodes(fs_info
);
1226 clear_bit(BTRFS_FS_STATE_REMOUNTING
, &fs_info
->fs_state
);
1229 static int btrfs_remount(struct super_block
*sb
, int *flags
, char *data
)
1231 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
1232 struct btrfs_root
*root
= fs_info
->tree_root
;
1233 unsigned old_flags
= sb
->s_flags
;
1234 unsigned long old_opts
= fs_info
->mount_opt
;
1235 unsigned long old_compress_type
= fs_info
->compress_type
;
1236 u64 old_max_inline
= fs_info
->max_inline
;
1237 u64 old_alloc_start
= fs_info
->alloc_start
;
1238 int old_thread_pool_size
= fs_info
->thread_pool_size
;
1239 unsigned int old_metadata_ratio
= fs_info
->metadata_ratio
;
1242 btrfs_remount_prepare(fs_info
);
1244 ret
= btrfs_parse_options(root
, data
);
1250 btrfs_remount_begin(fs_info
, old_opts
, *flags
);
1251 btrfs_resize_thread_pool(fs_info
,
1252 fs_info
->thread_pool_size
, old_thread_pool_size
);
1254 if ((*flags
& MS_RDONLY
) == (sb
->s_flags
& MS_RDONLY
))
1257 if (*flags
& MS_RDONLY
) {
1259 * this also happens on 'umount -rf' or on shutdown, when
1260 * the filesystem is busy.
1262 sb
->s_flags
|= MS_RDONLY
;
1264 btrfs_dev_replace_suspend_for_unmount(fs_info
);
1265 btrfs_scrub_cancel(fs_info
);
1266 btrfs_pause_balance(fs_info
);
1268 ret
= btrfs_commit_super(root
);
1272 if (fs_info
->fs_devices
->rw_devices
== 0) {
1277 if (fs_info
->fs_devices
->missing_devices
>
1278 fs_info
->num_tolerated_disk_barrier_failures
&&
1279 !(*flags
& MS_RDONLY
)) {
1281 "Btrfs: too many missing devices, writeable remount is not allowed\n");
1286 if (btrfs_super_log_root(fs_info
->super_copy
) != 0) {
1291 ret
= btrfs_cleanup_fs_roots(fs_info
);
1295 /* recover relocation */
1296 ret
= btrfs_recover_relocation(root
);
1300 ret
= btrfs_resume_balance_async(fs_info
);
1304 ret
= btrfs_resume_dev_replace_async(fs_info
);
1306 pr_warn("btrfs: failed to resume dev_replace\n");
1309 sb
->s_flags
&= ~MS_RDONLY
;
1312 btrfs_remount_cleanup(fs_info
, old_opts
);
1316 /* We've hit an error - don't reset MS_RDONLY */
1317 if (sb
->s_flags
& MS_RDONLY
)
1318 old_flags
|= MS_RDONLY
;
1319 sb
->s_flags
= old_flags
;
1320 fs_info
->mount_opt
= old_opts
;
1321 fs_info
->compress_type
= old_compress_type
;
1322 fs_info
->max_inline
= old_max_inline
;
1323 mutex_lock(&fs_info
->chunk_mutex
);
1324 fs_info
->alloc_start
= old_alloc_start
;
1325 mutex_unlock(&fs_info
->chunk_mutex
);
1326 btrfs_resize_thread_pool(fs_info
,
1327 old_thread_pool_size
, fs_info
->thread_pool_size
);
1328 fs_info
->metadata_ratio
= old_metadata_ratio
;
1329 btrfs_remount_cleanup(fs_info
, old_opts
);
1333 /* Used to sort the devices by max_avail(descending sort) */
1334 static int btrfs_cmp_device_free_bytes(const void *dev_info1
,
1335 const void *dev_info2
)
1337 if (((struct btrfs_device_info
*)dev_info1
)->max_avail
>
1338 ((struct btrfs_device_info
*)dev_info2
)->max_avail
)
1340 else if (((struct btrfs_device_info
*)dev_info1
)->max_avail
<
1341 ((struct btrfs_device_info
*)dev_info2
)->max_avail
)
1348 * sort the devices by max_avail, in which max free extent size of each device
1349 * is stored.(Descending Sort)
1351 static inline void btrfs_descending_sort_devices(
1352 struct btrfs_device_info
*devices
,
1355 sort(devices
, nr_devices
, sizeof(struct btrfs_device_info
),
1356 btrfs_cmp_device_free_bytes
, NULL
);
1360 * The helper to calc the free space on the devices that can be used to store
1363 static int btrfs_calc_avail_data_space(struct btrfs_root
*root
, u64
*free_bytes
)
1365 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1366 struct btrfs_device_info
*devices_info
;
1367 struct btrfs_fs_devices
*fs_devices
= fs_info
->fs_devices
;
1368 struct btrfs_device
*device
;
1373 u64 min_stripe_size
;
1374 int min_stripes
= 1, num_stripes
= 1;
1375 int i
= 0, nr_devices
;
1378 nr_devices
= fs_info
->fs_devices
->open_devices
;
1379 BUG_ON(!nr_devices
);
1381 devices_info
= kmalloc(sizeof(*devices_info
) * nr_devices
,
1386 /* calc min stripe number for data space alloction */
1387 type
= btrfs_get_alloc_profile(root
, 1);
1388 if (type
& BTRFS_BLOCK_GROUP_RAID0
) {
1390 num_stripes
= nr_devices
;
1391 } else if (type
& BTRFS_BLOCK_GROUP_RAID1
) {
1394 } else if (type
& BTRFS_BLOCK_GROUP_RAID10
) {
1399 if (type
& BTRFS_BLOCK_GROUP_DUP
)
1400 min_stripe_size
= 2 * BTRFS_STRIPE_LEN
;
1402 min_stripe_size
= BTRFS_STRIPE_LEN
;
1404 list_for_each_entry(device
, &fs_devices
->devices
, dev_list
) {
1405 if (!device
->in_fs_metadata
|| !device
->bdev
||
1406 device
->is_tgtdev_for_dev_replace
)
1409 avail_space
= device
->total_bytes
- device
->bytes_used
;
1411 /* align with stripe_len */
1412 do_div(avail_space
, BTRFS_STRIPE_LEN
);
1413 avail_space
*= BTRFS_STRIPE_LEN
;
1416 * In order to avoid overwritting the superblock on the drive,
1417 * btrfs starts at an offset of at least 1MB when doing chunk
1420 skip_space
= 1024 * 1024;
1422 /* user can set the offset in fs_info->alloc_start. */
1423 if (fs_info
->alloc_start
+ BTRFS_STRIPE_LEN
<=
1424 device
->total_bytes
)
1425 skip_space
= max(fs_info
->alloc_start
, skip_space
);
1428 * btrfs can not use the free space in [0, skip_space - 1],
1429 * we must subtract it from the total. In order to implement
1430 * it, we account the used space in this range first.
1432 ret
= btrfs_account_dev_extents_size(device
, 0, skip_space
- 1,
1435 kfree(devices_info
);
1439 /* calc the free space in [0, skip_space - 1] */
1440 skip_space
-= used_space
;
1443 * we can use the free space in [0, skip_space - 1], subtract
1444 * it from the total.
1446 if (avail_space
&& avail_space
>= skip_space
)
1447 avail_space
-= skip_space
;
1451 if (avail_space
< min_stripe_size
)
1454 devices_info
[i
].dev
= device
;
1455 devices_info
[i
].max_avail
= avail_space
;
1462 btrfs_descending_sort_devices(devices_info
, nr_devices
);
1466 while (nr_devices
>= min_stripes
) {
1467 if (num_stripes
> nr_devices
)
1468 num_stripes
= nr_devices
;
1470 if (devices_info
[i
].max_avail
>= min_stripe_size
) {
1474 avail_space
+= devices_info
[i
].max_avail
* num_stripes
;
1475 alloc_size
= devices_info
[i
].max_avail
;
1476 for (j
= i
+ 1 - num_stripes
; j
<= i
; j
++)
1477 devices_info
[j
].max_avail
-= alloc_size
;
1483 kfree(devices_info
);
1484 *free_bytes
= avail_space
;
1488 static int btrfs_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
1490 struct btrfs_fs_info
*fs_info
= btrfs_sb(dentry
->d_sb
);
1491 struct btrfs_super_block
*disk_super
= fs_info
->super_copy
;
1492 struct list_head
*head
= &fs_info
->space_info
;
1493 struct btrfs_space_info
*found
;
1495 u64 total_free_data
= 0;
1496 int bits
= dentry
->d_sb
->s_blocksize_bits
;
1497 __be32
*fsid
= (__be32
*)fs_info
->fsid
;
1500 /* holding chunk_muext to avoid allocating new chunks */
1501 mutex_lock(&fs_info
->chunk_mutex
);
1503 list_for_each_entry_rcu(found
, head
, list
) {
1504 if (found
->flags
& BTRFS_BLOCK_GROUP_DATA
) {
1505 total_free_data
+= found
->disk_total
- found
->disk_used
;
1507 btrfs_account_ro_block_groups_free_space(found
);
1510 total_used
+= found
->disk_used
;
1514 buf
->f_namelen
= BTRFS_NAME_LEN
;
1515 buf
->f_blocks
= btrfs_super_total_bytes(disk_super
) >> bits
;
1516 buf
->f_bfree
= buf
->f_blocks
- (total_used
>> bits
);
1517 buf
->f_bsize
= dentry
->d_sb
->s_blocksize
;
1518 buf
->f_type
= BTRFS_SUPER_MAGIC
;
1519 buf
->f_bavail
= total_free_data
;
1520 ret
= btrfs_calc_avail_data_space(fs_info
->tree_root
, &total_free_data
);
1522 mutex_unlock(&fs_info
->chunk_mutex
);
1525 buf
->f_bavail
+= total_free_data
;
1526 buf
->f_bavail
= buf
->f_bavail
>> bits
;
1527 mutex_unlock(&fs_info
->chunk_mutex
);
1529 /* We treat it as constant endianness (it doesn't matter _which_)
1530 because we want the fsid to come out the same whether mounted
1531 on a big-endian or little-endian host */
1532 buf
->f_fsid
.val
[0] = be32_to_cpu(fsid
[0]) ^ be32_to_cpu(fsid
[2]);
1533 buf
->f_fsid
.val
[1] = be32_to_cpu(fsid
[1]) ^ be32_to_cpu(fsid
[3]);
1534 /* Mask in the root object ID too, to disambiguate subvols */
1535 buf
->f_fsid
.val
[0] ^= BTRFS_I(dentry
->d_inode
)->root
->objectid
>> 32;
1536 buf
->f_fsid
.val
[1] ^= BTRFS_I(dentry
->d_inode
)->root
->objectid
;
1541 static void btrfs_kill_super(struct super_block
*sb
)
1543 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
1544 kill_anon_super(sb
);
1545 free_fs_info(fs_info
);
1548 static struct file_system_type btrfs_fs_type
= {
1549 .owner
= THIS_MODULE
,
1551 .mount
= btrfs_mount
,
1552 .kill_sb
= btrfs_kill_super
,
1553 .fs_flags
= FS_REQUIRES_DEV
,
1555 MODULE_ALIAS_FS("btrfs");
1558 * used by btrfsctl to scan devices when no FS is mounted
1560 static long btrfs_control_ioctl(struct file
*file
, unsigned int cmd
,
1563 struct btrfs_ioctl_vol_args
*vol
;
1564 struct btrfs_fs_devices
*fs_devices
;
1567 if (!capable(CAP_SYS_ADMIN
))
1570 vol
= memdup_user((void __user
*)arg
, sizeof(*vol
));
1572 return PTR_ERR(vol
);
1575 case BTRFS_IOC_SCAN_DEV
:
1576 ret
= btrfs_scan_one_device(vol
->name
, FMODE_READ
,
1577 &btrfs_fs_type
, &fs_devices
);
1579 case BTRFS_IOC_DEVICES_READY
:
1580 ret
= btrfs_scan_one_device(vol
->name
, FMODE_READ
,
1581 &btrfs_fs_type
, &fs_devices
);
1584 ret
= !(fs_devices
->num_devices
== fs_devices
->total_devices
);
1592 static int btrfs_freeze(struct super_block
*sb
)
1594 struct btrfs_trans_handle
*trans
;
1595 struct btrfs_root
*root
= btrfs_sb(sb
)->tree_root
;
1597 trans
= btrfs_attach_transaction_barrier(root
);
1598 if (IS_ERR(trans
)) {
1599 /* no transaction, don't bother */
1600 if (PTR_ERR(trans
) == -ENOENT
)
1602 return PTR_ERR(trans
);
1604 return btrfs_commit_transaction(trans
, root
);
1607 static int btrfs_unfreeze(struct super_block
*sb
)
1612 static int btrfs_show_devname(struct seq_file
*m
, struct dentry
*root
)
1614 struct btrfs_fs_info
*fs_info
= btrfs_sb(root
->d_sb
);
1615 struct btrfs_fs_devices
*cur_devices
;
1616 struct btrfs_device
*dev
, *first_dev
= NULL
;
1617 struct list_head
*head
;
1618 struct rcu_string
*name
;
1620 mutex_lock(&fs_info
->fs_devices
->device_list_mutex
);
1621 cur_devices
= fs_info
->fs_devices
;
1622 while (cur_devices
) {
1623 head
= &cur_devices
->devices
;
1624 list_for_each_entry(dev
, head
, dev_list
) {
1627 if (!first_dev
|| dev
->devid
< first_dev
->devid
)
1630 cur_devices
= cur_devices
->seed
;
1635 name
= rcu_dereference(first_dev
->name
);
1636 seq_escape(m
, name
->str
, " \t\n\\");
1641 mutex_unlock(&fs_info
->fs_devices
->device_list_mutex
);
1645 static const struct super_operations btrfs_super_ops
= {
1646 .drop_inode
= btrfs_drop_inode
,
1647 .evict_inode
= btrfs_evict_inode
,
1648 .put_super
= btrfs_put_super
,
1649 .sync_fs
= btrfs_sync_fs
,
1650 .show_options
= btrfs_show_options
,
1651 .show_devname
= btrfs_show_devname
,
1652 .write_inode
= btrfs_write_inode
,
1653 .alloc_inode
= btrfs_alloc_inode
,
1654 .destroy_inode
= btrfs_destroy_inode
,
1655 .statfs
= btrfs_statfs
,
1656 .remount_fs
= btrfs_remount
,
1657 .freeze_fs
= btrfs_freeze
,
1658 .unfreeze_fs
= btrfs_unfreeze
,
1661 static const struct file_operations btrfs_ctl_fops
= {
1662 .unlocked_ioctl
= btrfs_control_ioctl
,
1663 .compat_ioctl
= btrfs_control_ioctl
,
1664 .owner
= THIS_MODULE
,
1665 .llseek
= noop_llseek
,
1668 static struct miscdevice btrfs_misc
= {
1669 .minor
= BTRFS_MINOR
,
1670 .name
= "btrfs-control",
1671 .fops
= &btrfs_ctl_fops
1674 MODULE_ALIAS_MISCDEV(BTRFS_MINOR
);
1675 MODULE_ALIAS("devname:btrfs-control");
1677 static int btrfs_interface_init(void)
1679 return misc_register(&btrfs_misc
);
1682 static void btrfs_interface_exit(void)
1684 if (misc_deregister(&btrfs_misc
) < 0)
1685 printk(KERN_INFO
"btrfs: misc_deregister failed for control device\n");
1688 static int __init
init_btrfs_fs(void)
1692 err
= btrfs_init_sysfs();
1696 btrfs_init_compress();
1698 err
= btrfs_init_cachep();
1702 err
= extent_io_init();
1706 err
= extent_map_init();
1708 goto free_extent_io
;
1710 err
= ordered_data_init();
1712 goto free_extent_map
;
1714 err
= btrfs_delayed_inode_init();
1716 goto free_ordered_data
;
1718 err
= btrfs_auto_defrag_init();
1720 goto free_delayed_inode
;
1722 err
= btrfs_delayed_ref_init();
1724 goto free_auto_defrag
;
1726 err
= btrfs_interface_init();
1728 goto free_delayed_ref
;
1730 err
= register_filesystem(&btrfs_fs_type
);
1732 goto unregister_ioctl
;
1734 btrfs_init_lockdep();
1736 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
1737 btrfs_test_free_space_cache();
1740 printk(KERN_INFO
"%s loaded\n", BTRFS_BUILD_VERSION
);
1744 btrfs_interface_exit();
1746 btrfs_delayed_ref_exit();
1748 btrfs_auto_defrag_exit();
1750 btrfs_delayed_inode_exit();
1752 ordered_data_exit();
1758 btrfs_destroy_cachep();
1760 btrfs_exit_compress();
1765 static void __exit
exit_btrfs_fs(void)
1767 btrfs_destroy_cachep();
1768 btrfs_delayed_ref_exit();
1769 btrfs_auto_defrag_exit();
1770 btrfs_delayed_inode_exit();
1771 ordered_data_exit();
1774 btrfs_interface_exit();
1775 unregister_filesystem(&btrfs_fs_type
);
1777 btrfs_cleanup_fs_uuids();
1778 btrfs_exit_compress();
1781 module_init(init_btrfs_fs
)
1782 module_exit(exit_btrfs_fs
)
1784 MODULE_LICENSE("GPL");